Automobile door reinforcing member

ABSTRACT

An automobile door reinforcing member consists of a twin pipes exercising high strength and rigidity. This automobile reinforcing member has been developed by the structure wherein a pair of pipes are formed relatively from an original sheet material by the joint surface as being a middle portion of an original sheet in width direction, the fold-back faces consist of the outer side faces of the pipes extending laterally from said joint surface, the outer wall faces extending from said outer side faces of the pipes, and the inner side faces of the pipes extending from said outer wall faces, the inner wall faces extending from said fold-back faces to the joint surface, and the welding portions extending from said inner wall faces, with forming these portions to lateral pipes relatively with bending the fold-back faces, folding boundary mark between the inner wall face and the welding portion in valley-shaped, and putting those welding portions onto the joint surface situated at interval between said pipes, and then welding both of welding portions and the joint surface for integrating.

BACKGROUND OF THE INVENTION

[0001] 1. Field of the Invention

[0002] The present invention relates to an automobile door reinforcing member being arranged inside of an automobile door, so as to protect crewmen on the vehicle by absorbing impact in the collision from a side face.

[0003] 2. Description of the Related Art

[0004] A strict safety level for automobiles provides a built-in type of the automobile door reinforcing members, such as the side beam or the impact protection beam. For these automobile door reinforcing members, there are many proposals to achieve miniaturization, lightening, high strengthening on demand. For instance, these are shown in U.S. Pat. Nos. 5,580,120, 5,813,718, 5,820,202, 5,992,922 and 6,020,039 in the states, furthermore, in Japanese Patent Application Laid-Open No. 216684/1996, No. 141368/1997, No. 215059/1995, No. 244456/1996, and No. 086172/1997.

[0005] The purpose of an automobile door reinforcing member is to protect crewmen by absorbing impact in the collision from a side face. In order to achieve the purpose of mentioned above, there are integral formed products such as formed by processing an original sheet or formed by transforming a pipe cross-section. More numbers of pipes and more complicated structures of pipe cross-section, strength of products becomes higher. These are preferable structures as shown in U.S. Pat. No. 5,580,120, which is structured by one pipe but the sectional structure is complicated, U.S. Pat. Nos. 5,813,718, 5,820,202, Japanese Patent Application Laid-Open No. 244456/1996 and 086172/1997. In Japanese Patent Application Laid-Open No. 086172/1997, it indicates that, in particular, the necessity of high strengthened materials are required in the case of structured by one pipe.

[0006] Thus, in Japanese Patent Application Laid-Open No. 141368/1997 and No. 215059/1995 structured by only one pipe, improvement of strength are provided by welding. On the other hand, in U.S. Pat. No. 5,813,718, Japanese Patent Application Laid-Open No. 216684/1996, No. 244456/1996 and No. 086172/1997 structured by annexed two pipes, a welding process is avoided to save accuracy after forming. Also, Japanese Patent Application Laid-Open No. 215059/1995 indicates that, in the case of avoiding the welding process, the rigidity is inferior when low strength materials are used. For this indication, however, there is a problem as sudden deterioration of strength by buckling even if high strength materials are used. Such sudden deterioration of strength is deeply anxious for providing a sufficient safety under the actual collision from a side face.

[0007] From the above, the demands imposed on an automobile door reinforcing member are (1) miniaturizing and lightening an reinforcing member in order to improve its installation space, (2) providing a sufficient strength and rigidity under the use of low strength materials, and (3) preventing an occurrence of buckling. Accordingly, the object of the present invention is to provide an automobile door reinforcing member consisting of the twin pipes which shows sufficient strength and rigidity by welding process with low strength materials are used.

SUMMARY OF THE INVENTION

[0008] The present invention is an automobile door reinforcing member consists of the structure wherein a pair of pipes are formed relatively from an original sheet material by: the joint surface as being a middle portion of an original sheet in width direction, the fold-back faces consist of the outer side faces of the pipes extending laterally from said joint surface, the outer wall faces extending from said outer side faces of the pipes, and the inner side faces of the pipes extending from said outer wall faces, the inner wall faces extending from said fold-back faces to the joint surface, and the welding portions extending from said inner wall faces, forming these portions to lateral pipes relatively with bending the fold-back faces, folding boundary mark between the inner wall face and the welding portion in valley-shaped, and putting those welding portions onto the joint surface situated at interval between said pipes, and then welding both of welding portions and the joint surface for integrating.

[0009] As a basic installation aspect, this automobile door reinforcing member is installed between an outer panel and an inner panel of an automobile door, located the joint surface and the outer side faces of pipes toward the outside of an automobile, in the same time, long distance direction of pipes is in front and back direction of an automobile.

[0010] The pipe formed by folding the fold-back faces of an original sheet having welding portions at the inner wall faces extending from the folded-back faces. By being welded said welding portions and the joint surface integrally, sufficient bond-strength of pipes with the joint surface is obtained. The welding portions and the joint surface are superposed, thus, a simple, cheap and continuous welding process is applicable with the spot-welding.

[0011] To improve the structural strength of a pipe itself, a quenching to an intermediate portion of pipe is effective for an automobile door reinforcing member of the present invention. In practice of the product, in concerning of a stress variance putting on pipes, a product consists of a beam structure with twin tong supporting pipes at installation parts formed to both ends of a product, and said quenching performs on an intermediate portion of pipe.

[0012] A continuous roll forming is available for pipe forming process. Accordingly, an automobile door reinforcing member of the present invention is manufactured efficiently by the original sheet supplying continuously in sequential order of a roll forming process to a spot-welding process. Furthermore, as a cutting/separating process, the product is obtained by cutting and separating the tubular article in every product length, which completed processing continuously with passing through the roll forming process and the spot-welding process. By necessity, the bending process that bends a product according with an automobile door and said quenching process are installed before a cutting/separating process. Despite these bending process and quenching process, productivity is not impaired by reason of the operation of these processes passing through the spot-welding process continuously. The installation parts of a product being obtained by cutting and separating are formed by crushing both ends of pipe. The installation part being formed by crushing pipe has a structure overlapped two original sheets. This makes structural strength higher.

[0013] An absorption performance of impact as an automobile door reinforcing member is substantially influenced by shapes of the pipe cross-section. An automobile door reinforcing member of the present invention is formed to be; (1) a pipe consists of an approximately annular cross-section folding the outer side face of the pipe, the outer wall face and the inner side face of the pipe continuously in arc-shaped, (2) a pipe consists of an approximately oval cross-section obtained by bending the outer side face of the pipe and the inner side face of the pipe in arc-shaped, and by extending the outer wall face in linearly from the outer side face of the pipe to the inner side face of the pipe, and further (3) a pipe consists of an approximately square cross-section obtained by bending the outer side face of the pipe in arc-shaped, and by extending the outer wall face and the inner side face of the pipe in linearly. The cross-section of (1) is a basis of an automobile door reinforcing member of the present invention, and (2) is a cross-section adapting to the thickness of automobile door (=a space between the outer panel and the inner panel) by extending the outer wall face. Further, an automobile door reinforcing member of the present invention has a cross-section as (3) to avoid an amount of deformation influenced mutually by the outer side face of the pipe, the outer wall face and the inner side face of the pipe.

[0014] A structure of the joint surface dents relatively against a form of the outer side face of the pipe. A performance of impact absorption by an automobile door reinforcing member depends on an amount of deformation occurring in the outer side face, the joint surface and the inner side face. If an amount of deformation of the inner side face of pipe is larger than the outer face of pipe, there is some fear of buckling as that an impact absorption capacity deteriorates suddenly after a particular point of impact absorption. Therefore, the joint surface is dented relatively against the outer side face of the pipe, then, the central axis line of an automobile door reinforcing member is devated toward an inner side face of the pipe. Accordingly, a small gap of an amount of deformation between the outer and the inner side faces of the pipe is achieved by improving the modulus of section of the inner side face of the pipe, then, restraining an amount of deformation of the inner side face of the pipe. A dent of the joint surface is simultaneously formed at the roll forming process serving as bend of the fold-back face. Further, a level difference of a dented joint surface functions as a kind of the rib, and, for example, it restrains generation of strain in said bending process.

BRIEF DESCRIPTION OF THE DRAWINGS

[0015]FIG. 1 is a perspective view showing the state which is laid an automobile door reinforcing member 1 upward a side of an internal surface of the automobile as an use form of the present invention.

[0016]FIG. 2 is an enlarged view of A-A cross-section in FIG. 1.

[0017]FIG. 3 is a sectional view showing an aspect of basic installation according to A-A cross-section in FIG. 1.

[0018]FIG. 4 is a block-diagram showing an example of production line for linear products.

[0019]FIG. 5 is a block-diagram adding a bending process to production line in FIG. 4.

[0020]FIG. 6 is a perspective view showing the state of an original sheet driven by the production line.

[0021]FIG. 7 is a perspective view explaining the roll forming process in production line.

[0022]FIG. 8 is a perspective view explaining the spot-welding process in production line.

[0023]FIG. 9 is a grossly enlarged sectional view showing an automobile door reinforcing member which consisted of oval sectional pipes.

[0024]FIG. 10 is a grossly enlarged sectional view showing an automobile door reinforcing member which indented a joint surface.

[0025]FIG. 11 is a grossly enlarged sectional view showing an automobile door reinforcing member which consisted of pipes with approximately square cross-section.

[0026]FIG. 12 is a grossly enlarged sectional view showing the other example of an automobile door reinforcing member which consisted of pipes with approximately square cross-section.

DETAIL DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0027] For convenience, applied configurations of the present invention are explained while referring to attached drawings as follows.

[0028] As seen in FIG. 1 and FIG. 2, an automobile door reinforcing member 1 of the present invention is similar to conventional products visually. The welding portions 7,7 extending form both pipes 6,6 and the joint surface 5 are unified by spot-welding (spot-welding print S). An automobile door reinforcing member 1 which is cut off in every product length is formed the installation part 8,8 (a bolt pore etc, are not shown) by crushed its both ends. As being clear from above, an automobile reinforcing member 1 has a layered structure (the welding portion 7—the welding portion 7—the joint surface 5) integrated by welding of that the welding portion 7,7 being both folded margins of the original sheet superposes to the joint surface 5. In addition, a structure consists of a part (shown as the fold-back face 14) of the original sheet formed the twin pipes 6,6 by bulged out, and, the fitting parts 8,8 layered the both ends in long distance direction of the product.

[0029] For an attached form, the cases of which are faced the joint surface 5 toward outside or inside of an automobile are proposable. As shown in FIG. 3, a basic attached form is to be the case of which is faced the joint surface 5 toward outside of an automobile. In other words, in the space between the outer panel 10 and the inner panel 11 which are forming an automobile door, the joint surface 5 turns toward outside of an automobile. In the same time, a long distance direction of the pipes 6 is synchronized to be placed in direction of long distance of an automobile. An external force of a side collision is absorbed by stretch (modification) of the pipes 6,6.

[0030] The present invention produces the automobile door reinforcing member 1 continuously from the original sheet 2; completes processing through the roll forming process 3 and the spot-welding process 4, then, cuts and separates in every product length at the cutting/separating process 12. An example of a production line is shown in FIG. 4 and FIG. 5. The original sheet 2 (high-tensile rigid plate, for example) is supplied continuously by the uncoiler 13. As shown in FIG. 6, the original sheet 2 is a long sheet material which is lasting in every product length. In FIG. 6, each boundary marks of the joint surface 5, the folded-back faces 14 (consisting of the outer side face 21 of the pipe, the outer wall face 19 and the inner side face 20 of the pipe), the inner wall face 22 and the welding portion 7 illustrates with short dash line. A portion of the joint surface 5 so that the welding portions 7,7 are superposed illustrates with hatching. Further, at the basic attached form, “In” shown in FIG. 6 belongs to the inside of an automobile, on the other hand, “Out” belongs to the outside of an automobile. These illustrations are shown in the same way in FIG. 7 and FIG. 8.

[0031] As shown in FIG. 7, the original sheet is to be formed the pipe 6 by bending each folded-back faces 14 (consisting of the outer side face 21 of the pipe, the outer wall face 19 and the inner side face 20 of the pipe) continuously at the roll forming process 3. A boundary mark between the inner wall face 22 extending from the inner side face 20 of the pipe and the welding portion 7 is bent in valley folding.

[0032] First, at the roll forming process 3, the welding portion 7 shown as the far side in FIG. 7 is fitted on to the joint surface 5, and subsequently, the other welding portion 7 shown as the near side is fitted on to them. The pipe 6 shown as approximately annular sectional view in FIG. 2 is formed by folding the outer side face 21 of the pipe, the outer wall face 19 and the inner side face 20 of the pipe gradually and equivalently. However, in the case of the approximately square sectional shaped pipe 6 for example, referring to FIG. 11, as hereinafter described, each of amounts of bending are changed gradually. In the case to dent the joint surface 5, furthermore, the dent is formed in this roll forming process by that folds of the joint surface 5 is shaped simultaneously or subsequently with forming of the pipe 6, then, dented the joint surface 5 relatively against the shape of the outer side face 21 of the pipe.

[0033] As seen in FIG. 8, at subsequently the spot welding process 4, the roller spot welding machines 15,15 are applied to the state which is put both of the welding portions 7,7 onto the join surface 5 from above and below so as to integrate the welding portion 7,7 and the joint surface 5 successively with spot-welding. In this example, after the spot welding process 4, an processing completes with the state ranged the tubular article 17 through the strain removal process 16. A quenching process is installed before or after the strain removal process so that improvement of structural strength of the pipe 6.

[0034] Further, a cutting/separating process for every product length is selective: (a) in the case of the straightened manufactures, shown as FIG. 4, it is supplied to the cutting/separating process 12 directly; (b) in the case of the curved manufactures, shown as FIG. 5, it is supplied to the cutting/separating process 12 through the bending process 18. In the end, the products are obtained by installing bolt mounting hole(s) to the fitting parts 8,8 formed by crushing both edges of the pipes 6,6 of each automobile door reinforcing members 1 at another production lines or devices (see FIG. 1).

[0035] Others of the above-mentioned illustration, an automobile door reinforcing member 1 of the present invention can adopt various kind of structures within the limit that is possible to secure productivity of the roll forming process and the spot-welding process.

[0036] The space between the outer panel 10 and the inner panel 11 (see FIG. 3) depends on a model of automobiles. In this case, as shown in FIG. 9, the approximately oval sectional pipes 6,6 is formed by extending the outer wall face linearly. Adjusting oval shape of pipes depends on the thickness of an automobile door reinforcing member.

[0037] Further, as shown in FIG. 10, the joint surface 5 is dented relatively against the outer side face 21 of the pipe so as to prevent buckling of an automobile door reinforcing member 1 structurally and to improve performance of impact absorption. Said dent displaces the central axis line G toward inner side of automobiles, and achieves a small gap of amount of deformation between the outer side face 21 and the inner side face 20 of the pipes. A little quantity of dent 6 is sufficient.

[0038] As seen in FIG. 11, in order to prevent buckling of the pipe 6, each cross-section of the pipes 6,6 is closed to form an approximately square cross-section. An approximately square sectional pipe 6 obtains high performance to absorb impact by means of its structure to prevent buckling. Besides, as seen in FIG. 12, an approximately square cross-section of the pipe 6 is preferably formed symmertrically so that the different amount of stretch between the outer side face 21 and the inner side face 21 of the pipe is decreased. This pipe 6, in addition, enhances structural strength with inflated the inner side face 20 of the pipe, the outer side face 21 of the pipe and the outer side face 19. Amount of dent 6 to the joint surface 5 depends on bulge of the inner side face 20 of the pipe relatively.

[0039] As seen from the above, an automobile door reinforcing member of the present invention has a simple structure and the following advantages as compared to the current products. First, (1) the simple structure miniaturizes products. However, in spite of miniaturizing, a necessary and a sufficient performance is obtained by structure of the present invention. In other words, (2) low strength materials relatively are available as a result of structure of the present invention which is higher strength and rigidity compared to a current automobile door reinforcing member in same extent. These high strength and rigidity are achieved by the complete closed-structure obtaining as a result of welding the pipe formed in the folded-back faces. Said welding is sufficient to be a continuous spot-welding, thus, a smart production efficiency provides the continuous production using a roll forming. Besides, the pipe exercises high strength and rigidity relatively to the fitting part as a result of quenching to the intermediate part except the fitting part, thus, superior performance to absorb impact is obtained. 

What is claimed is:
 1. An automobile door reinforcing member comprising of a structure wherein a pair of pipes are formed relatively from an original sheet by: a joint surface as being a middle portion of the original sheet in width direction, fold-back faces formed by an outer side faces of the pipes extending laterally from said joint surface, outer wall faces extending from said outer side faces of the pipes, and inner side faces of the pipes extending from said outer wall faces, inner wall faces extending from said fold-back faces to the joint surface, and welding portions extending from said inner wall faces; forming these portions to lateral pipes relatively with bending said fold-back faces, folding boundary marks between said inner wall faces and said welding portions in valley-shaped, and putting those welding portions onto said joint surface situated at interval between said pipes, and then welding both of welding portions and said joint surface for integrating.
 2. An automobile door reinforcing member according to claim 1, wherein pipes are quenched at the intermediate part in length direction.
 3. An automobile door reinforcing member according to claim 1, wherein folded-back faces forming pipes shapes to approximately annular cross-section with folding back said outer side faces of the pipes, said outer wall faces and said inner side faces of the pipes continuously in arc-shaped.
 4. An automobile door reinforcing member according to claim 1, wherein folded-back faces forming pipes shapes to approximately oval cross-section obtained by bending said outer side faces of the pipes and said inner side faces of the pipes in arc-shaped, and by extending said outer wall faces in linearly between these side faces of the pipe.
 5. An automobile door reinforcing member according to claim 1, wherein folded-back faces forming pipes shapes to approximately square cross-section obtained by bending said outer side face of the pipes in arc-shaped, and by extending said outer wall faces and said inner side faces of the pipes in linearly.
 6. An automobile door reinforcing member according to claim 1, wherein said joint surface obtained by denting relatively against a shape of said outer side faces of the pipes. 